In general, a reel is classified into a spinning reel which uses paste or earthworm as a bait, and a bait casting reel which uses an artificial bait made as a model (e.g., small fish or worm).
Here, in the bait casting reel, a spool is installed on the inside of a reel main body equipped with a rotary handle at one end, when turning the rotary handle, the relaxed fishing line is wound on a spool, and a reel cover that supports the spool is coupled to the other end of the main body.
With such a bait casting reel, fishing is performed by gradually rotating the rotary handle after the artificial bait is tied to the tip of the fishing line and is thrown into the water.
At this time, the artificial bait is moved in a winding direction of the fishing line, while the fishing line is wound on the spool, and the fish confuses and bites it as a living bait.
Thus, since the bait casting reel repeats the operation after throwing the fishing line, a phenomenon in which the fishing line wound on the spool is frequently twisted occurs, and thus, it is necessary to separate the reel cover to untwist the twisted fishing line.